| 摘要 |
PURPOSE:To produce a double sink having high strength and high rigidity, by forming a pair of sinks with use of a blank having a thick center part on the rear side and as a result avoiding a thin side wall at the center of the said sinks. CONSTITUTION:A hollow part 8 is formed at a part of one of rollers 6 and 7, and a coil material 5 is rolled by the rollers 6 and 7 to form a thick part 2 on a single side of the material 5. The material 5 is turned into a blank 1 through an annealing process. A gentle slope is formed around the thick part 2 on the rear side 1a of the blank 1, and the part 2 is limited within the area where the formation is expected for a pair of sinks and the center part between these sinks as shown by 2-dot chain lines 3a and 4a. The blank 1 is put on a dice to unify the sinks 3 and 4. In such a way, a thin side wall part can be avoided at the center part of a pair of sinks even in the case of a deep drawing process to increase the strength and the rigidity. |
